Thanks for the AIS input ideas.
What are the mechanics/electronics of coupling the VHF/AIS radio into the serial port. Would it be better to use the USB port instead of the RS-232 9-pin since new computers (new replacements) have only USB ports?
Thank you all ! !

I've got the GX2150, which was the model before they figured out they could put GPS in the thing for little extra, so I have to run NMEA in to get my position, and NMEA out to send AIS info to my chartplotter and PC.

NMEA 0183 is a serial connection, so you'll need an old RS232 9-pin serial cable to use to interface to the unit with 1 or 2 wires, then you'll need a USB-Serial converter (since like you said new computers don't have old serial ports).

There's plenty of info out there if you google it, but if you're not good at tinkering and baud rates then you might consider hiring somebody.

I don't know how to use radar, no one told me how to use AIS. It's 2am, 45 miles off the east coast of Australia, it's blowing 25-30 kts, raining and cold with a 2 metre swell and the odd wave spraying the cockpit. I took a quick look around. Not a single light to be seen anywhere. I was going to take the easy way and get under the spray hood, (I'm not the only person on watch here), but I thought I'd just take a look at the chart plotter down the wet end. There straight ahead with the pointy bit pointing directly at us is a grey triangle. I put the cursor on it. It's big, 9 miles away, heading exactly our way and it's doing 22kts. We're doing 9kts. So without AIS I'm not sure I'd be writing this, or I might have had a much more exciting tale to tell. Some excitement I can do without.

I don't know how to use radar, no one told me how to use AIS. It's 2am, 45 miles off the east coast of Australia, it's blowing 25-30 kts, raining and cold with a 2 metre swell and the odd wave spraying the cockpit. I took a quick look around. Not a single light to be seen anywhere. I was going to take the easy way and get under the spray hood, (I'm not the only person on watch here), but I thought I'd just take a look at the chart plotter down the wet end. There straight ahead with the pointy bit pointing directly at us is a grey triangle. I put the cursor on it. It's big, 9 miles away, heading exactly our way and it's doing 22kts. We're doing 9kts. So without AIS I'm not sure I'd be writing this, or I might have had a much more exciting tale to tell. Some excitement I can do without.

Thanks for the testimony. One more vote for "better to have than not to have". I get the point that radar and transceiver AIS is superior (if you know how to use them effectively), but that does not mean AIS receivers on a VHF are a useless frill. Clearly, they have utility.

Well shoot, I just invested $36,000 on top of the line radar, GPS, chartplotters, AIS transeiver and flux capacitors based on the advice I got in this thread, and now a couple of you chime in saying that an AIS receiver IS better than nothing!

But seriously, I just received my SH 2200 combo unit, along with an articulating arm to mount it. Reading the manual, this sucker is SLICK! I'll install it this weekend, just in time for my Gulf Islands voyage.

Well shoot, I just invested $36,000 on top of the line radar, GPS, chartplotters, AIS transeiver and flux capacitors based on the advice I got in this thread, and now a couple of you chime in saying that an AIS receiver IS better than nothing!

But seriously, I just received my SH 2200 combo unit, along with an articulating arm to mount it. Reading the manual, this sucker is SLICK! I'll install it this weekend, just in time for my Gulf Islands voyage.

Thanks again for the advice all.

I would advise, based on my own experience, to just focus on the "quick install", assuming you have an MMSI at hand to plug into to it to get the full pop. Later, you will find semi-buried menus, easy enough to get to after poking around, of course, that have such useful functions as "qualified DSC calls" which can semi-automated a MAYDAY by sending specifics along with your MMSI and lat/lon. So when you hit Big Red, you aren't just yelling "MAYDAY", but "MAYDAY, Fire"; "MAYDAY, Abandoning", and "MAYDAY, Adrift". Those one-word qualifications will affect in part the manner in which you are replied to and, if necessary, are rescued. "Abandoning", for instance, means those clever SARs are looking for something based on set and drift from your now-empty or sunk boat.

There's a lot of cool stuff packed into that unit. There's nav functions using the GPS onboard that partially sub for a plotter, for instance. Obvious that there could have been, but it's icing on the cake. Another add-on: My 12 year old was on the foredeck and I was in a sealed pilothouse Monday afternoon; the optional PA has a "listen" function and I was able to hear him giving anchoring instructions from 20 feet forward. That's just one instance where the extra 50 bucks for the PA horn means I don't have to replace PTT Cobras for anchoring or squint to see handsignals from the foredeck at midnight.

And no, I didn't get this for free, nor do I work for SH! I'm just pleased with the unit and the full exploitation of what a GPS/AIS receive/VHF could be.

I don't know how to use radar, no one told me how to use AIS. It's 2am, 45 miles off the east coast of Australia, it's blowing 25-30 kts, raining and cold with a 2 metre swell and the odd wave spraying the cockpit. I took a quick look around. Not a single light to be seen anywhere. I was going to take the easy way and get under the spray hood, (I'm not the only person on watch here), but I thought I'd just take a look at the chart plotter down the wet end. There straight ahead with the pointy bit pointing directly at us is a grey triangle. I put the cursor on it. It's big, 9 miles away, heading exactly our way and it's doing 22kts. We're doing 9kts. So without AIS I'm not sure I'd be writing this, or I might have had a much more exciting tale to tell. Some excitement I can do without.

Hi Grayp5 and welcome to the forum,

Don't mean to jump on your first post but I have to say that at least for me, a ship 9 miles away is not yet an urgent concern and I would not consider an imminent threat to my boat. I have passed through choke points that were high traffic areas where a mile clearance or even less was common.

I once did the math on the minimum time a sailboat would have to avoid a collision, assuming a worst case scenario. I chose 21 kts as the ship speed, the beam of the largest ship in the world of 69 meters and a sailboat speed of 6 kts. The exact numbers but more or less this. 6 kts boat speed is about 3 meters/second (10'/second for the metrically challenged). 21 kts ship speed is about 10 meter/second.

This means if you saw this ship headed directly towards your boat it would take less than 30 seconds to cross the full 69 meter beam. If you were dead ahead and only had to cross half the beam of the ship then 15 seconds. In distance the ship is traveling about 10 meters/second so the 30 seconds it would take to pass completely across her bow would equate to 300 meters or 150 meters for the halfway trip.

Disclaimers

1. Of course I am not advocating coming anywhere this close to a ship. That would be the height of folly.
2. I am also not advocating one ignore ships that are still miles away from your boat or waiting to take action at the last second.
3. Also not advocating one play loose with the Coregs nor avoid taking early action to comply as the burdened or give way vessel and allow the approaching ship adequate time to see and understand your actions and for them to act appropriately.

BUT, if you didn't have AIS or radar and a ship loomed out of the darkness close at hand you would probably live to tell about it and a ship even a mile away you will have plenty of time to avoid.

__________________
The water is always bluer on the other side of the ocean.

Hi Skipjack, I'd say one persons safe margin is another's near miss. Sure the next time I stuck my head up to look around out of the spray hood 15 minutes later, in the rain I may have seen a bulker in a 2 mile range with a closing speed of 32 kts, or it's light may have been obscured by the genoa, who knows. My observation might have been ok, even though I had 4 hours sleep in three days.

My point is that AIS is cheap and saved me that situation and was so simple to use. The skipper who is very experienced (he almost took the Americas cup off you folks some years back), was somewhat relieved that in trying conditions that I did look at the plotter, and he took immediate avoiding action giving them a 2 mile margin. Sure we would have missed....it's a big ocean out there. Just ask Jessica Watson.

Looks like your and my post are off the point of the original post. I'll leave posting to you in future.

Hi Skipjack, I'd say one persons safe margin is another's near miss. Sure the next time I stuck my head up to look around out of the spray hood 15 minutes later, in the rain I may have seen a bulker in a 2 mile range with a closing speed of 32 kts, or it's light may have been obscured by the genoa, who knows. My observation might have been ok, even though I had 4 hours sleep in three days.

My point is that AIS is cheap and saved me that situation and was so simple to use. The skipper who is very experienced (he almost took the Americas cup off you folks some years back), was somewhat relieved that in trying conditions that I did look at the plotter, and he took immediate avoiding action giving them a 2 mile margin. Sure we would have missed....it's a big ocean out there. Just ask Jessica Watson.

Looks like your and my post are off the point of the original post. I'll leave posting to you in future.

Hi Gray,

This discussion is a slight digression from the original question but I'm pretty sure that after 5 pages, 70 posts, good answers to the original question and numerous other off topic comments our little drift will not incur the wrath of the internet.

Hope you don't think I am targeting you for criticism because I am sincerely trying not to. Absolutely your attention to the oncoming vessel was warranted, I just think the level of concern and danger you expressed was possibly just slightly too much?

Part of my motivation for the comments is to perhaps take a little stress out of sailing for others, maybe for you as well. The main point I was trying to get across was that you can still easily avoid a collision at much closer distances than you might think. Not saying to wait until the last second but collision avoidance can be easily and safely managed at a mile or two.

Where I usually cruise if I became concerned about every ship within a 9 mile radius I would be in a constant panic. Places like the Gulf Stream off the SE Florida coast or the main passages in and out of the Caribbean you could easily have 8-10 ships in that range approaching your position from different directions. In my years of sailing never had a real close call with a ship but twice came close to collisions with other sailboats, in one case over 100 miles from land.

I have not yet added AIS and will wait to add a full transceiver as I believe it is as important for ships to know where I am as it is for me to know where they are. That being said I certainly start watching ships as soon as they are in visual range and start tracking their course. If it looks like a close approach and I am the giveway vessel I take action while they are still miles away.

__________________
The water is always bluer on the other side of the ocean.

Had the SH2150, replaced it with a SH2000 when I got a transponder. Seems the 2150 doesn't have a way to filter yourself. Food for thought if you're considering a later upgrade to transmitting ability.

As far as OpenCPN, the AIS display capability works right out of the gate. Just set up a NMEA (or IP in my case) connection and you're good to go.

A note about the SH2000... The manual, and Panbo both said that a major drawback was the radio's inability to accept GPS sentences on the high speed port, that it wanted them only on the low speed. I'm not sure when they changed, but mine is just happy as a clam accepting both sentence types on the high speed port.

I have the watchmate transponder with the wifi, the SH2000, and OpenCPN and it's a great combination. I have a Garmin plotter in the cockpit (and it's good), but the watchmate's ability to translate NMEA2000 and NMEA0814 to IP makes OpenCPN a breeze and so much more powerful. I highly recommend it.

Had the SH2150, replaced it with a SH2000 when I got a transponder. Seems the 2150 doesn't have a way to filter yourself. Food for thought if you're considering a later upgrade to transmitting ability.

This isn't true unless you programmed them with different MMSI numbers. The SH2150 knows to ignore its ownship's MMSI AIS signal.

This isn't true unless you programmed them with different MMSI numbers. The SH2150 knows to ignore its ownship's MMSI AIS signal.

Mark

So, what you are saying is you use the same MMSI # for the transmitter as well as the 2150? As they are separate units.

I have a SH 2150 which I haven't installed, or had time to read the manual yet.
I have only had for a couple of years.
I was not going to enable the AIS receiver facility. We don't even have dsc on vhf here, only hf.( IIRC'ly)